The present invention relates to electronic weighing scales of the type generating an electric signal ("weight signal") which comprises a direct current component ("DC-component") indicative of the weight and a periodic oscillatory signal component superposed on the DC-component due to vibration and inherent in the electronic weighing scale.
The weight signal produced by a weighing mechanism including a load cell or other elastic structure comprises a DC-component indicative of the true weight of product weighed and a periodic oscillatory signal component caused by loading shock and vibrations in the elastic structure. In the case of a hanging scale or crane scale adapted to weigh the product which is directly or indirectly hung on the scale, the hung product is apt to oscillate also causing a periodic oscillatory signal component to be superposed on the DC-component indicating the true weight.
Analog filters or non-recursive filters composed of a multiplier, an adder, and a delay circuit have been used to remove the periodic oscillatory signal component from weight signals. However, if these filters are used to completely remove the periodic oscillatory signal component the response time of the weight signal indicating the weight is slowed because of the remarkably low frequency of the periodic oscillatory signal component.